The Dark Side of the Universe: How Black Holes Became Supermassive

New model from Brookhaven Lab physicists suggests the early universe experienced a phase transition that formed supermassive black holes in a dark sector of physics

Black holes are one of the most compelling mysteries of the universe. Nothing, not even light, can escape a black hole. And at the center of nearly every galaxy there is a supermassive black hole that’s millions to billions of times more massive than the sun. Understanding black holes, and how they become supermassive, could shed light on the evolution of the universe.

Three physicists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have recently developed a model to explain the formation of supermassive black holes, as well as the nature of another phenomenon: dark matter. In a paper published in Physical Review Letters, theoretical physicists Hooman Davoudiasl, Peter Denton, and Julia Gehrlein describe a cosmological phase transition that facilitated the formation of supermassive black holes in a dark sector of the universe.

A cosmological phase transition is akin to a more familiar type of phase transition: bringing water to a boil. When water reaches the exact right temperature, it erupts into bubbles and vapor. Imagine that process taking place with a primordial state of matter. Then, shift the process in reverse so it has a cooling effect and magnify it to the scale of the universe.

“Before galaxies existed, the universe was hot and dense, and that is well established. How the universe cooled down to what we observe today is a matter of interest because we don’t have experimental data describing how that happened,” said Peter Denton. “We can predict what happened with the known particles because they interact often. But what if there are not-yet-known particles out there performing differently?”

More: The Dark Side of the Universe: How Black Holes Became Supermassive